Photographic apparatus and method

ABSTRACT

A self-developing camera for use with a photographic film unit including a photosensitive sheet and a second sheet secured in face-to-face relation by external binding strips secured to the lateral margins of the sheets and adapted to be processed to produce a visible image by a liquid processing agent distributed between the sheets in a uniform thin layer at least coextensive with the exposed area of the photosensitive sheet. The camera includes a pair of juxtaposed pressure-applying rolls for distributing the processing liquid between the sheets, and one of the rolls includes annular grooves near its ends for receiving lateral edge portions of the binding strips during movement of the film unit between the rolls to relieve the pressure on the edge portions of the binding strips while the medial sections of the rolls engage the sheets and are spaced apart by engagement of the end sections of the rolls with the binding strips at the lateral edges of the film unit.

United States Patent Bachelder 1 Mar. 7, 1972 [S4] PHOTOGRAPHICAPPARATUS AND METHOD 7 [72] Inventor: Albert J. Bachelder, Lexington,Mass.

[73] Assignee: Polaroid Corporation, Cambridge, Mass.

[22] Filed: Mar. 6, 1969 [21] Appl. No.: 804,819

Related 0.8. Application Data [63] Continuation-impart of Ser. No.744,912, July 15,

[52] U.S.Cl ..96/29, 95/13 [51] Int. 1 ..G03c 5/54 [58] Fiel otSeareh..96/29, 76; 95/13 [56] References Cited UNlTElj STATES PATENTS3,152,529 10/1964 Erlichman ..95/13 3,473,925 10/1969 Milligan et al.3,479,184 11/1969 Land et al ..96/29 X Primary Examiner-Norman G.Torchin Assistant Examiner-John L. Goodrow Attorney-Brown and Mikulkaand Robert E. Corb [57] ABSTRACT A self-developing camera for use with aphotographic film unit including a photosensitive sheet and a secondsheet secured in face-to-face relation by external binding stripssecured to the lateral margins of the sheets and adapted to be processedto produce a visible image by a liquid processing agent distributedbetween the sheets in a uniform thin layer at least coextensive with theexposed area of the photosensitive sheet. The camera includes a pair ofjuxtaposed pressure-applying rolls for distributing the processingliquid between the sheets, and one of the rolls includes annular groovesnear its ends for receiving lateral edge portions of the binding stripsduring movement of the film unit between the rolls to relieve thepressure on the edge portions of the binding strips while the medialsections of the rolls engage the sheets and are spaced apart byengagement of the end sections of the rolls with the binding strips atthe lateral edges of the film unit.

13 Claims, Drawing Figures PATENTEBMA 7 I972 sum 1 0r 2 INVENTOR. AIBERT,J. BACHELDER B/wum a/nd fifiula,

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ATTORNEYS This application is a continuation-in-part of the copending-U.S. Pat. application of A. J. Bachelder et al. Ser. No.

744,912, filed July 15,1968.

The aforementioned application and the US. patent of Edwin H. Land No.3,415,644, granted Dec. 10, 1968, disclosed a self-developing film unitincluding a photosensitive sheet and a transparent second orimage-receiving sheet bound together in face-to-face relation by bindingelements secured to the outsides of the sheets around and to the marginsthereof. The photosensitive and second sheets are rectangular, and thebinding elements, in addition to retaining the sheets together, alsofunction as a mask defining a rectangular area of the photosensitivesheet adapted to be exposed through the transparent sheet and thereafterprocessed to produce a visible image between the sheets. This image isformed, preferably by diffusion transfer of image-forming substancesfrom the image-recording sheet, to an image-receiving layer on thesecond sheet and is visible through the second sheet which is retainedin superposition with the photosensitive sheet after processing iscomplete. Processing is effected by advancing the film unit between apairof pressure-applying members to spread a viscous processing liquidin a thin layer between the sheets from a rupturable container coupledto the sheets adjacent a transverse edge of the area to be processed.The processing liquid is required to be spread in a uniformly thin layerat least coextensive with the exposed area of the photosensitive sheetand extending at least to and preferably beyond the edges of the exposedarea defined by the edges of the'binding elements.

The processing liquid is distributed within the film unit between thephotosensitive and second sheets by moving the film unit, commencingwith the container, through a conversion passage between a pair ofpressure-applying members, preferably rollers mounted for rotation aboutsubstantially parallel axes. At the start of the liquid distributionprocess, the liquid is dispensed from the container between the sheetsas an elongated mass located adjacent a transverse edge of the exposedarea and extending substantially from side-to-side thereof, and is thenadvanced toward the opposite edge of the exposed area as the film unitis advanced between the pressure-applying members to form a thin layerof uniform thickness at least coextensive with the exposed area. Thepressure-applying members (rolls) are, as a rule, resiliently biasedtoward one another, and the thickness of the layer of liquid is afunction of the spacing between the rolls in the region of the exposedarea. This spacing between the medial portions of the pressure-applyingmembers is, in turn, a function of the thickness of the lateral marginsof the film unit which are engaged between the end sections of thepressure-applying members and retain the pressure-applying members apartfrom one another. Thus, to provide a space between the sheets in theregion of the exposed area in which the processing liquid isdistributed, the combined thicknesses of the binding elements and sheetsat the lateral margins of the film unit are greater than the combinedthicknesses of the sheets in the region interme;iate the bindingelements defining the exposed area, so that the spacing between thesheets in the region in which the processing liquid is spread will beapproximately equal to the total thickness of the binding elements ateach lateral edge.

in a preferred form of film unit described in the aforementionedapplication and patent, the binding elements defining ,he lateral edgesof the exposed area take the general form of thin strips of sheetmaterial adhered around and to the lateral margins of the sheets suchthat each binding element includes two lateral marginal sections, eachadhered to a lateral margin of one of the sheets. Thus, the spacingbetween the medial portions of the sheets in the region of the exposedarea will be approximately twice the thickness of the sheet material ofwhich the binding elements are formed.

It will be apparent that during spreading of the processing liquid, thepressure-applying members will tend to retain the lateral margins of thesheets in face-to-face contact while the medial portions of the sheetsin the region of the exposed area are permitted to separate under thepressure of the processing liquid; and that there will be transitionregions near the lateral edges of the exposed area in which the sheetsare deformed or bent apart from one another and are neither in contactnor spaced by a distance approximating the required thickness of thelayer of processing liquid. Accordingly, the thickness of the layer ofprocessing liquid in these narrow lateral transition regions borderingthe exposed area will not be uniform, and the quantity of liquidavailable for the image formation process will be insufficient forproper image formation. There is a tendency for this condition ofinsufficient liquid processing reagent near the lateral edges of theexposed area to be worsened due to the fact that portions of thephotosensitive and second sheets, lying outside of and immediatelyadjacent the exposure area and underlying the binding elements, absorbthe processing liquid, thereby further reducing the quantity of liquidavailable to process the exposed photosensitive sheet and form an imagein the lateral regions of the film unit immediately adjacent the bindingelements.

This problem of insufiicient liquid processing agent at the lateraledges of the exposed area of the photosensitive sheet is partiallyalleviated by distributing the processing liquid beyond the lateraledges of the exposed area into the region between the sheets underlyingthe combined masking and binding element. To facilitate distribution ofthe processing liquid laterally beyond the edges of the exposed area,the edges of the binding element at each side of the image area areoffset from one another. Specifically, the lateral edges of the lateralmarginal sections of the binding elements secured to the second orimage-receiving sheet (through which the photosensitive sheet is exposedand the image is viewed) are located inwardly toward the center of thefilm unit beyond the lateral edges of the lateral marginal sections ofthe binding elements secured to the photosensitive sheet, therebypermitting spacing of the portions of the sheets underlying the lateralmarginal sections of the binding element secured to the imagereceivingsheet.

An object of the present invention is to provide, during processing of afilm unit of the type described, additional spacing between the sheetsof the film unit in lateral regions immediately adjacent the exposedarea of the film unit in order to insure that there will be sufficientliquid available for complete processing of the photosensitive sheet andformation of a visible image in the exposed area completely to thelateral edges thereof.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the apparatus possessing theconstruction, combination of elements and arrangement of parts and theprocess of the several steps and the relation and order of one or moresuch steps with respect to each of the others, which are exemplified inthe following detailed disclosure, and the scope of the application ofwhich will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings wherein:

FIG. 1 is a perspective view, partially in section, with parts brokenaway of a self-developing film unit adapted to be employed in theapparatus and method of the invention;

FIG. 2 is an elevational view, partially in section, of a selfdevelopingcamera embodying the invention and adapted to perform the methodthereof; and

FIG. 3 is an enlarged view illustrating the apparatus and method of theinvention.

Reference is now made to FIG. 2 of the drawings wherein there isillustrated a camera 10 embodying the invention. Camera 10 is of thetype shown and described in detail in the copending US. Pat. applicationof Edwin H. Land et al. Ser. No. 655,850, filed July 25, [967, and theUS. Pat. applications of lrving Erlichman, Ser. No. 713,766, filed Mar.l8,

H968, and Ser. No. 763,883, filed Sept. 30, 1968. This camera is of thefolding type, comprising a housing including three relatively movablesections, namely, a rear or main section 12, a forward section 14, andan intermediate section 16, all pivotally coupled to one another formovement between a folded position and the erect or operative positionshown. Forward section 14 incorporates a lens and shutter assembly whichmay be of a conventional type and also includes a source of power forthe camera such as an electrical motor generally designated 18.

The rear or main housing section 12 of the camera is adapted to containa film pack or assembly of photographic film units and includes meansfor locating the film pack with a film unit thereof in position forexposure. For this purpose, the rear housing section includes a forwardwall 20 having a rectangular opening 22 therein for transmitting lightto a film unit positioned for exposure behind or to the rear of wall 20;sidewalls 21; and a rear wall 24 cooperating with the forward and sidewalls to provide a chamber for receiving and containing a film pack. Adoor 26 is located at the rear of housing section 12 to provide accessto the interior of the housing section to permit loading of a film packinto the camera.

Intermediate housing section 16 includes a mirror (not shown) located atan angle with respect to the optic axis of the lens and the plane of thefilm for reflecting light from the lens within housing section 14 towarda film unit positioned within rear housing section 12 behind forwardwall 20. The camera housing also includes a connecting member 28pivotally joined to forward housing section 14 and intermediate housingsection 16 to assist in supporting the housing sections in the operativeposition shown, and a collapsible bellows 30 coupled with the housingsections and cooperating therewith to provide a light-tight chamberthrough which light is transmitted from the lens in housing section 14via the mirror in housing section 16 to a film unit positioned forexposure within housing section 12.

Camera is shown with a film pack or assemblage 32 mounted within thecamera in position for exposure. Film pack 32 includes generallyparallelepiped-shaped container 34 having a forward wall 40 providedwith a rectangular exposure aperture 42 surrounded by a flange adaptedto be engaged in opening 22 of forward wall for properly locating theforward wall of the film pack; an end wall 44 provided with a narrowslot 46 through which a film unit exposed within the container may bewithdrawn therefrom; and side walls 45 for holding and guiding the filmunits. The film pack is shown as containing a plurality of film unitsdesignated 48 and shown in greater detail in FIGS. 1 and 3 of thedrawings. The film units are arranged in stacked relation on a supportplate 50 biased by springs 52 toward forward wall 40 of container 34 forsupporting the forwardmost film unit against the forward wall acrossaperture 42 in position to be exposed by light transmitted throughaperture 42 and with an end (leading) of the film unit aligned with slot46.

Film units 48 may be designed to produce a visible image by any of anumber of different image-forming processes and, in the preferred form,are designed for the production of a positive photographic print in fullcolor formed by a diffusion transfer process in which a photographicimage-recording medium, including a photosensitive material such assilver halide, is exposed to light to form an image (latent) therein andis treated by wetting with a liquid processing agent to develop theimage in the image-recording medium, form an imagewise distribution oftransferable image-providing substances, and transfer theimage-providing substances by diffusion to an image-receptive stratum inwhich they are immobilized to form a visible positive image.

A preferred embodiment of the film unit includes all of the materialsand reagents required to produce a full-color photographic print by aprocess such as disclosed in the U. S. Pat. of Howard G. Rogers No.2,983,606, granted May 9, l96l, and includes the materials incorporatedin a structure such as described in detail in the aforementioned3,4l5,644 patent.

.Film unit.48 is illustrated as comprising a rectangular photosensitiveor image-recording sheet 54 and a rectangular second or image-receivingsheet 56 substantially coextensive with the photosensitive sheet andarranged in superposed face-to-face relation therewith. A typicalphotosensitive sheet, described in greater detail in the aforementionedpatents and adapted to be employed to produce multicolor transfer imagesobtained utilizing dye developers, comprises an opaque support for alayer of photosensitive material comprising strata containingselectively sensitized overlying silver halide emulsions and havingassociated therewith dye developers. Such a photosensitive layer mayinclude three sets of silver halide emulsion and associated dyedeveloper strata comprising, for example, red, green, and blue silverhalide emulsion strata having associated therewith respectively, a cyandye developer, a magenta dye developer, and a yellow dye developer. Thedye developers are preferably selected for their ability to providecolors useful in producing a full-color image by a subtractive processin which each dye developer is immobilized or precipitated in exposedareas of the associated silver halide emulsion stratum as a consequenceof development thereof, while in unexposed areas and partially exposedareas of the emulsions, the dye developer remains unreacted anddiffusible, thereby providing an imagewise distribution of unoxidizeddye developer which is transferred, at least in part, by diffusion to animage-receiving layer without altering the wise distribution of the dyedeveloper, to form a reversed in positive image of the latent image inthe emulsion.

The second or image-receiving sheet 56 comprises a transparent,dimensionally stable support and an image-receiving layer providing anappropriate environment for the formation of a diffusion transfer image,e.g., a dyeable layer, particularly an image formed in terms of dyestransferred from a photsensitive layer located in adjacent, face-to-facerelation with the image-receiving layer.

Sheets 54 and 56 are arranged in superposed, face-to-face relation withthe photosensitive and image-receiving layers located innermost betweenthe sheets and are secured together by a binding element 58 in the formof a rectangular sheet larger than either of the photosensitive orimage-receiving sheets and secured to the two sheets at the marginsthereof. Binding element 58 is in the general form of a frame having alarge rectangular opening 60 defining the extent of the image producedin the film unit by exposure of the photosensitive sheet by lighttransmitted through the imagereceiving sheet. Opening 22 is surroundedby lateral edge portions 62, a leading end portion 64, and a trailingend portion 66, adhered to the outer surface of image-receiving sheet 56at the margins thereof. Lateral edge portions 62 and trailing endportion 66 function as binding strips adhered to the imagereceivingsheet, extending around the lateral edges and one transverse edge of thesuperposed sheets and adhered to the outer surface of the photosensitivesheet 54 at the margins thereof. The lateral and transverse edges of thebinding element 58 defining exposure aperture 60 and the limits of theexposed area are offset from the lateral and transverse edges of theelement; that is, they are spaced inwardly from the edges of thephotosensitive and image-receiving sheets a greater distance than thelateral and transverse edges of the sections of the binding elementsecured to the photosensitive sheet for reasons which will be explainedin greater detail hereinafter. Binding element 58 is opaque to actiniclight and performs the multiple functions of retaining thephotosensitive and image-receiving sheets in face-to-face relation;confining the liquid between the sheets preventing escape thereof fromthe film unit during spreading of the processing liquid; of a maskdefining the exposed area of the area in which a visible transfer imageis formed; and of a spacer for controlling the thickness of the layer ofprocessing liquid distributed between the photosensitive andimage-receiving sheets. in a preferred form of film unit adapted toproduce a reflection print surrounded by a white border and viewedagainst a white background, at least binding element 58 is formed of awhite material to provide a more aesthetically pleasing product.

Film unit 48 includes a container 68 of processing liquid 70, thecontainer being of the type shown in U. S. Pat. No. 2,543,181, formed byfolding a rectangular blank of a liquidimpervious sheet materialmedially and sealing the marginal sections of the blank to one anotherto form a cavity for containing processing liquid 70. The seal betweenlongitudinal marginal sections 72 of the container is weaker than theend seals so that, upon the application of a predetermined compressiveforce to the walls of the container in the region of the liquid-filledcavity, there will be generated within the liquid hydraulic pressuresufficient to separate longitudinal marginal sections 72 throughouttheir length to form an elongated discharge mouth, at least equal inlength to the length of the cavity and the width of the area defined byopening 60, through which the processing liquid is discharged. Container68 is attached to the sheets at the transverse edges thereof oppositetrailing end portion 66 of binding element 58, preferably with thelongitudinal edge of the container located closely adjacent or buttedagainst the edges of the sheets and with the discharge passage of thecontainer aligned with the facing surfaces of the sheets. The containeris coupled to the sheets by means including end portion 64 of bindingelement 58 which is secured to one of longitudinal marginal sections 72of the container and by a strip 74 secured to the transverse marginalsection of sheet 54 and to the other longitudinal marginal section 72 ofthe container. End portion 64 and strip 74 are secured to the containerand sheets 54 and 56 so as to bridge the gap between the container andsheets and cooperate to provide a liquidtight seal between the marginalsections of the container defining the discharge passage and the sheetsand form a conduit for conducting the liquid from the container betweenthe sheets at the transverse marginal portions thereof.

As previously noted, the film unit is adapted to be processed byapplying compressive pressure to the film unit along a line extendingtransversely of the film unit and substantially perpendicular to thelateral edges thereof and to the exposed area. Compressive pressure isapplied progressively, commencing in the region of the container andthence toward the opposite or trailing end of the film unit by movingthe film unit, container foremost, through a passage or gap between apair of juxtaposed, pressure-applying members. Compressive pressure isapplied initially to container 68 generating hydraulic pressure withinliquid 70 effecting rupture of the bond between marginal sections 72 anddischarge of the liquid in the form of an elongated mass between sheets54 and 56. Continued movement of the film unit between thepressure-applying members causes advancement of the mass of liquidbetween the sheets toward the opposite end thereof and spreading of theliquid as a thin layer 96 of predetermined thickness between and incontact with the photosensitive and image-receiving layers.

The processing liquid includes an agent for increasing the viscosity ofthe liquid so as to promote opening of the discharge passage of thecontainer throughout substantially its entire length and facilitate thedischarge of the liquid from the container and spreading of the liquidbetween the sheets. For this purpose, the liquid should be quite viscousand contain a film-forming material in quantities sufficient to impart aviscosity in excess of 1,000 centipoises at a temperature of C., andpreferably of the order of 1,000 to 200,000 centipoises at saidtemperature.

It has been the practice, in order to insure spreading of the processingliquid in a layer of predetermined uniform thickness at leastcoextensive with the exposed area, to provide a quantity of processingliquid in the container in excess of that required to form the layerbetween the sheets. Accordingly, film units of this type include meansfor collecting and retaining any excess processing liquid and preventingit from escaping from the film unit, and in the form shown, these meansinclude structure for providing a trapping space within the film unit atthe trailing end thereof in which excess processing liquid is collectedand retained. To form this trapping space, image-receiving sheet 56includes a trailing end section 76 extending beyond the trailing(transverse) edge of photosensitive sheet 54 to provide a space betweenthe image-receiving sheet and trailing end section 66 of the bindingelement. Trailing end section 76 of image-receiving sheet 56 isembossed, near its lateral edges, toward the photosensitive sheet toprovide ribs 78 for spacing the pressure-applying members apart from oneanother during movement of the trailing end of the film unit between thepressure-applying members so as to provide a space between the trailingend section 76 of the image-receiving sheet and the trailing end section66 of the binding element.

A typical pair of pressure-applying members suitable for distributingthe processing liquid within the film unit is illustrated in FIGS. 2 and3 of the drawings as comprising a pair of rollers 80 and 82 mounted injuxtaposition for rotation about axes lying in a common plane. Rollers80 and 82 have cylindrical, peripheral surfaces which cooperate toprovide a convergent passage through which the film unit is moved, forexample, by rotating the rollers, and the surface includes linear(axial) portions which are disposed substantially parallel with oneanother and define the narrowest portion of the convergent passagebetween the rollers. Other forms of pressure-applyin g members may beemployed including, for example, nonrotary members having surfacesdefining a convergent gap, the surfaces including linear portions thatare parallel and define the narrowest portion of the gap. Although thepressure-applying members may be mounted in fixed position with respectto one another so as to provide a passage therebetween having fixeddimensions or mounted a fixed minimum distance apart, in the preferredform shown and adapted to use with a film unit comprising materials ofvarying thickness (e,g., the container is thinner than the film unit inthe region of the binding element), the rollers are mounted for movementtoward and away from one another and are resiliently biased toward oneanother to apply compressive pressure to all portions of the film unit(e.g., to effect complete emptying of the container).

In the camera shown in FIG. 2 of the drawings, rollers 80 and 82 aremounted in juxtaposition within the rear housing section 12 and arecoupled through gears 84 and a suitable transmission (not shown) tomotor 14 for driving the rolls to advance the film unit therebetween.Rolls 80 and 82 are mounted closely adjacent end wall 44 of filmcontainer 34 with the bite of the rolls aligned with withdrawal slot 46,and means are provided for advancing an exposed film unit from thecontainer through slot 46 into the bite of the rolls. Theselast-mentioned means include a reciprocating film engagement member 86including end section 88 adapted to extend into the film pack through anopening in forward wall 40 to engage the container 68 (e.g., an openingtherein) of the forwardmost film unit and move the container into thebite of the rolls. A typical mechanism for reciprocating member 86includes a pin (not shown), mounted on an end of roll 80 or gear 84,engaged in a slot 90 in a reciprocating link 92 coupled with member 86for reciprocating the latter during rotation of roll 80. For furtherdetails of a film-feeding system of the foregoing type, reference may behad to the aforementioned application Ser. No. 713,766.

During distribution of the processing liquid, the liquid is advancedbetween the sheets ahead of the pressure-applying rolls as an elongatedmass at least equal in length to the width of the exposed area andextending from side to side thereof. This elongated mass of liquid, asit is advanced between the sheets, forces the sheets apart to provide aspace therebetween in which the liquid forms a layer. The depth of thisspace and the thickness of the layer is dependent upon a number offactors, principally, the spacing between the pressure-applying rolls atthe narrowest portion of the gap between the rolls and the thicknessesof the photosensitive and image-receiving sheets. Proper spacing betweenthe medial portions of the surface of the rolls, that is, those portionsof the roll surfaces which engage the sheets within the region of theexposed area, is obtained by biasing end portions of the rolls intoengagement with lateral marginal sections of the film unit,specifically, into engagement with the binding strips provided bylateral edge portions 62 of binding element 58. The thickness of eachlateral marginal portion of the film unit is equal to the aggregatethickness of the photosensitive and image-receiving sheets and twothicknesses of the binding element, so that the spacing between thesheets and the thickness of the layer of liquid is at least equal totwice the thickness of the binding element which, in a typical filmunit, may be approximately 0.002 inch and provide for a liquid layerapproximately 0.004 inch thick.

As previously noted, the pressure-applying rolls tend to retain thelateral marginal portions of the photosensitive and image-receivingsheets in face-to-face contact while the medial portions of the sheetsare permitted to separate to provide a space in which the processingliquid is distributed as a thin layer so that there will be a transitionregion intermediate these two regions in which the facing surfaces ofthe sheets is neither in contact nor separated by the requisitedistance. The layer of liquid in these transition regions varies inthickness from nothing in the region where the sheets are inface-to-face contact, to a maximum within the exposed area defined byopening 60 in binding element 58. To insure that there will besufficient liquid in narrow lateral regions immediately adjacent theedges of opening 60, the lateral edges of the portions of bindingelement 58 secured to the photosensitive sheet are located outwardly andparallel with the lateral edges of opening 60 in the binding element toenable separation of the photosensitive and image-receiving sheets inregions outside of the exposed area and underlying binding element 58.As the processing liquid is distributed between the sheets, it isabsorbed by the photosensitive and image-receiving layers both withinand without the exposed area of the film unit, so that there is atendency, due to absorption of the processing liquid by thephotosensitive and image-receiving layers located outside of andimmediately adjacent the exposed areas, for there to be insufficientliquid within the exposed area immediately adjacent the edges thereof.It is to provide a reservoir of liquid outside of and immediatelyadjacent the image area that the edges of the binding element are offsetfrom one another along each side of the film unit.

It has been found that the additional liquid provided by the offsetedges of the binding element, by itself, may be insufficient to providesufficient processing liquid at the edges of the image area defined byopening 60 in binding element 58 and that the presence of sufficientliquid can be assured by spreading the liquid in a layer of uniformthickness beyond the edges of the image area, particularly the lateraledges thereof. Thus, as shown in FIG. 3, the layer of processing liquidis continued in undiminished thickness outwardly beyond the lateraledges of opening 60 into the region underlying the portion of thebinding element secured to image-receiving sheet 56. To achieve thisresult, roller 80, which contacts the image-receiving sheet, is providedwith shallow annular recesses 94 in its peripheral surface, the radialdepth of each recess being approximately equal to the thickness of thebinding element, the axial spacing between recesses being slightly lessthan the spacing between the lateral edges of opening 60, and the widthof each recess being slightly greater than the distance by which thelateral edges of the binding element are offset from one another at eachside of the film unit. The film unit is guided between the rollers insuch a way that the extended lateral edge portions of the bindingelement secured to the image-receiving sheet are received with recesses94 permitting narrow portions of the photosensitive and image-receivingsheets in the regions outside of and immediately adjacent the exposurearea to be spaced apart substantially the same distance as the medialportions of the sheets within the image and thereby provide fordistribution of the processing liquid in a uniform layer laterallybeyond the edges of opening 60. Thus, because there is no diminution thethickness of the layer of processing liquid within or immediatelyadjacent the lateral edges of the image area, processing andimage-formation will be complete within the region of the image areaimmediately adjacent the lateral edges of opening 60 in the bindingelement.

During spreading of the processing liquid, the film unit is movedbetween the pressure-applying members in a direction substantiallyperpendicular to the axes of rolls and 82 and parallel with the lateraledges of opening 60 in binding element 58. The film is initially guidedinto the bite of the rolls by sidewalls 45 of container 34 which areproperly located with respect to recesses 94 in roll 80 by components ofthe camera, for example, forward wall 20 thereof. Once a film unit isengaged between the rolls and properly oriented with respect to the axesof rotation of the rolls, rotation of the rolls is effective to move thefilm unit in the desired direction with the lateral edge portions ofbinding element 58 properly aligned with and disposed within recesses94. Thus, sufficient processing liquid to effect uniform development ofthe photosensitive material and formation of a transfer image throughoutthe entire exposure (image) area is assured.

Since certain changes may be made in the above apparatus and processwithout departing from the scope of the invention herein involved, it isintended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

What is claimed is:

1. In photographic apparatus including means for processing arectangular area of photographic film unit including a thereof ofelements secured in face-to-face relation at their lateral edges byexternal binding strips defining the lateral edges of said exposed area,by distributing a liquid processing agent in a layer between saidelements at least coextensive with said exposed area, said meanscomprising a pair of members mounted in juxtaposition and defining apassage between said members for receiving and applying compressivepressure to an exposed film unit during movement thereof through saidpassage, said members including linear parallel surface portionsdefining the narrowest section of said passage, the improvementcomprising:

said surface portion of one of said members including shallow recessesspaced by a distance slightly less than the width of the exposed area ofa film unit adapted to be treated within said apparatus; and

means for moving said film unit into and through said passage betweensaid members with lateral edge portions of said binding strips disposedwithin said recesses and end sections of said surface portions of saidmembers engaged with and spaced apart by said binding strips at thelateral edges of said film unit.

2. Photographic apparatus as defined in claim 1 wherein said one memberis a cylindrical roller and said shallow recesses comprise annulargrooves in the peripheral surface of said roller.

3. Photographic apparatus as defined in claim 2 wherein said means formoving said film unit include means for rotating said roller inengagement with said film unit to advance said film unit between saidroller and the other of said members.

4. Photographic apparatus as defined in claim 3 wherein said othermember comprises a roller having a substantially cylindrical peripheralsurface.

5. Photographic apparatus as defined in claim 4 wherein said means formoving said film unit include means for rotating both of said rollers inengagement with a film unit to advance said film unit between saidrollers in a direction parallel with the lateral edges of the exposedarea of said film unit.

6. In a method of treating a photographic film unit including aphotosensitive, image-recording sheet and a second sheet secured inface-to-face relation by binding strips secured around and to thelateral margins of said sheets, to produce a visible image in said filmunit, an area of said photosensitive sheet intermediate said bindingstrips and extending thereto having been exposed to actinic radiationtransmitted through one of said sheets to produce an image in said areaof said photosensitive sheet and wherein a viscous liquid processingagent is introduced between said sheets adjacent a transverse edge ofsaid exposed area, the improvement comprising:

distributing a viscous liquid processing agent between said sheets in asubstantially uniform layer at least coextensive with said area andextending laterally beyond the edges thereof by moving said film unitlengthwise, beginning in the region of said viscous liquid, through agap defined by substantially parallel portions of the surfaces of a pairof juxtaposed pressure-applying members resiliently biased toward oneanother, one of said surfaces including a pair of recesses spaced apartfrom one another by a distance slightly less than the width of said areaand having a depth at least approximate equal to the thickness of saidbinding strips;

moving said film unit between and in engagement with said surfaces withsaid binding strips aligned with said recesses so that lateral edgeportions of said binding strips located inwardly from the lateral edgesof said film unit are located within said recesses and saidpressure-applying members are spaced apart from one another byengagement of said surfaces of said members with said binding strips inthe regions thereof immediately adjacent the lateral edges of said filmunit.

7. In the method of treating a photographic film unit defined in claim16, moving said film unit between said pressure-applying members withsaid second sheet located in contact with said one surface and portionsof said binding strips secured to said second sheet located within saidrecesses.

8. In the method of treating a photographic film unit defined in claim16 wherein said pressure-applying member providing said one surface is aroller, rotating said roller in contact with one of said sheets and saidbinding strips during movement of said film unit between saidpressure-applying members.

9. In a method of producing a visible photographic image utilizing afilm unit comprising a first sheet including a layer of a photosensitiveimage-recording medium and having generally parallel lateral edges, asecond sheet at least laterally coextensive with said first sheet andarranged in face-to-face relation therewith with said layer of saidimage-recording medium innermost and binding strips secured to theoutside of said sheets at the lateral margins thereof to retain saidsheets in face-to-face relation, said binding strips having longitudinaledges extending substantially parallel with said lateral edges of saidsheets and spaced inwardly therefrom toward one another to define thelateral edges of an area in which a visible image is fonned between saidsheets, said image-recording medium having been exposed to the action oflight to produce an image in said area bounded at opposite sides by saidlongitudinal edges of said binding strips and wherein a quantity of aviscous liquid processing agent is introduced between said sheetsadjacent a transverse edge of said area, the improvement comprising:

distributing said processing liquid between said sheets in a uniformlythin layer at least coextensive with said area and extending laterallybeyond the lateral edges of said area by moving said filrn unitlengthwise relative to and between a pair of pressure-applying membershaving juxtaposed pressSre-applying surfaces, one of which includesrecesses spaced from one another by a distance slightly less than thespacing between said lateral edges of said area and each having a depthat least substantially equal to the thickness of said binding strips;

during movement of said film unit between said pressureapplying members,guiding said film unit so that portions of said members engage saidbinding elements adjacent said lateral edges of said film unit and arespaced apart'by the combined thickness of said sheets and said bindingstrips and longitudinal edge portions of. said binding elements arereceived within said recesses to pennit the sepiration of said sheetswithin regions underlying said portions of binding strips duringmovement of said film unit between said pressure-applying members; and

reacting said processing agent with said exposed Imagerecording mediumto produce a visible image between said sheets extending at least tosaid lateral edges of said area.

10. In the method of producing a visible photographic image defined inclaim 16, exposing said image-recording medium through said secondsheet.

11. In the method of producing a visible photographic image defined inclaim 16 adapted to utilize pressure-applying members in which the widthof each of said recesses slightly exceeds the spacing between saidlongitudinal edges of said binding strips, guiding said film unit sothat edge portions of said binding strips secured to said other sheetare received within said recesses during movement of said film unitbetween said pressure'applying members.

12. In the method of producing a visible photographic image defined inclaim 11, exposing said image-recording medium by light transmittedthrough said second sheet.

13. In the method of producing a visible photographic image defined inclaim 17, wherein said one pressure-applying member is a roller, saidpressure-applying surface thereof is cylindrical, and said recesses ofsaid cylindrical press$re-applying surface include recessed cylindricalsurfaces having a radius differing from the first-mentioned cylindricalpressureapplying surface by approximately the thickness of said bindingstrips, rotating said roller in contact with one of said sheets duringmovement of said film unit between said pressure-applying members.

2. Photographic apparatus as defined in claim 1 wherein said one memberis a cylindrical roller and said shallow recesses comprise annulargrooves in the peripheral surface of said roller.
 3. Photographicapparatus as defined in claim 2 wherein said means for moving said filmunit include means for rotating said roller in engagement with said filmunit to advance said film unit between said roller and the other of saidmembers.
 4. Photographic apparatus as defined in claim 3 wherein saidother member comprises a roller having a substantially cylindricalperipheral surface.
 5. Photographic apparatus as defined in claim 4wherein said means for moving said film unit include means for rotatingboth of said rollers in engagement with a film unit to advance said filmunit between said rollers in a direction parallel with the lateral edgesof the exposed area of said film unit.
 6. In a method of treating aphotographic film unit including a photosensitive, image-recording sheetand a second sheet secured in face-to-face relation by binding stripssecured around and to the lateral margins of said sheets, to produce avisible image in said film unit, an area of said photosensitive sheetintermediate said binding strips and extending thereto having beenexposed to actinic radiation transmitted through one of said sheets toproduce an image in said area of said photosensitive sheet and wherein aviscous liquid processing agent is introduced between said sheetsadjacent a transverse edge of said exposed area, the improvementcomprising: distributing a viscous liquid processing agent between saidsheets in a substantially uniform layer at least coextensive with saidarea and extending laterally beyond the edges thereof by moving saidfilm unit lengthwise, beginning in the region of said viscous liquid,through a gap defined by substantially parallel portions of the surfacesof a pair of juxtaposed pressure-applying members resiliently biasedtoward one another, one of said surfaces including a pair of recessesspaced apart from one another by a distance slightly less than the widthof said area and having a depth at least approximate equal to thethickness of said binding strips; moving said film unit between and inengagement with said surfaces with said binding strips aligned with saidrecesses so that lateral edge portions of said binding strips locatedinwardly from the lateral edges of said film unit are located withinsaid recesses and said pressure-applying members are spaced apart fromone another by engagement of said surfaces of said members with saidbinding strips in the regions thereof immediately adjacent the lateraledges of said film unit.
 7. In the method of treating a photographicfilm unit defined in claim 16, moving said film unit between saidpressure-applying members with said second sheet located in contact withsaid one surface and portions of said binding strips secured to saidsecond sheet located within said recesses.
 8. In the method of treatinga photographic film unit defined in claim 16 wherein saidpressure-applying member providing said one surface is a roller,rotating said roller in contact with one of said sheets and said bindingstrips during movement of said film unit between said pressure-applyingmembers.
 9. In a method of producing a visible photographic imageutilizing a film unit comprising a first sheet including a layer of aphotosensitive image-recording medium and having generally parallellateral edges, a second sheet at least laterally coextensive with saidfirst sheet and arranged in face-to-face relation therewith with saidlayer of said image-recording medium innermost and binding stripssecured to the outside of said sheets at the lateral margins thereof toretain said sheets in face-to-face relation, said binding strips havinglongitudinal edges extending substantially parallel with said lateraledges of said sheets and spaced inwardly therefrom toward one another todefine the lateral edges of an area in which a visible image is formedbetween said sheets, said image-recording medium having been exposed tothe action of light to produce an image in said area bounded at oppositesides by said longitudinal edges of said binding strips and wherein aquantity of a viscous liquid processing agent is introduced between saidsheets adjacent a transverse edge of said area, the improvementcomprising: distributing said processing liquid between said sheets in auniformly thin layer at least coextensive with said area and extendinglaterally beyond the lateral edges of said area by moving said film unitlengthwise relative to and between a pair of pressure-applying membershaving juxtaposed pressure-applying surfaces, one of which includesrecesses spaced from one another by a distance slightly less than thespacing between said lateral edges of said area and each having a depthat least substantially equal to the thickness of said binding strips;during movement of said film unit between said pressure-applyingmembers, guiding said film unit so that portions of said members engagesaid binding elements adjacent said lateral edges of said film unit andare spaced apart by the combined thickness of said sheets and saidbinding strips and longitudinal edge portions of said binding elementsare received within said recesses to permit the separation of saidsheets within regions underlYing said portions of binding strips duringmovement of said film unit between said pressure-applying members; andreacting said processing agent with said exposed image-recording mediumto produce a visible image between said sheets extending at least tosaid lateral edges of said area.
 10. In the method of producing avisible photographic image defined in claim 16, exposing saidimage-recording medium through said second sheet.
 11. In the method ofproducing a visible photographic image defined in claim 16 adapted toutilize pressure-applying members in which the width of each of saidrecesses slightly exceeds the spacing between said longitudinal edges ofsaid binding strips, guiding said film unit so that edge portions ofsaid binding strips secured to said other sheet are received within saidrecesses during movement of said film unit between saidpressure-applying members.
 12. In the method of producing a visiblephotographic image defined in claim 11, exposing said image-recordingmedium by light transmitted through said second sheet.
 13. In the methodof producing a visible photographic image defined in claim 17, whereinsaid one pressure-applying member is a roller, said pressure-applyingsurface thereof is cylindrical, and said recesses of said cylindricalpressure-applying surface include recessed cylindrical surfaces having aradius differing from the first-mentioned cylindrical pressure-applyingsurface by approximately the thickness of said binding strips, rotatingsaid roller in contact with one of said sheets during movement of saidfilm unit between said pressure-applying members.